1. Field of the Invention
This invention relates to fasteners for reinforcing bars and more particularly relates to fasteners for holding reinforcing bars, such as rebar, in a fixed position.
2. Description of the Related Art
Reinforcing bar (“rebar”) is typically placed in concrete structures, such as concrete foundation blocks and solid concrete stem walls, during construction to provide tensile strength and rigidity. This is accomplished by suspending rebar in coplanar grid-like patterns within forms before filling the forms with cement. In order to maintain a stationary rebar configuration as concrete is poured, it is common practice to force rebar into the ground to a predetermined depth to hold the rebar configuration in a particular position and subsequently manually bind reinforcing bars together with wire ties where they intersect. The wire ties roll, stretch, and vibrate loose when heavy machinery is used nearby.
When laying cement, it is critical that the proper vertical orientation of the reinforcing bars be maintained as cement is poured into the forms. In the past, wooden stakes were pounded into the ground and used as measurement tools for laying a particular grade of cement. Recent laws now prohibit the use of wood in cement because wood tends to rot and disintegrate, thus compromising the structural integrity of the cement structure. Consequently, workers began using rebar itself for laying cement at a fixed grade.
The rebar pieces are generally cut into short lengths and pounded into the ground in a vertical orientation and fixed pattern, usually in a line. Longer, horizontal rebar members are laid near the base of each vertical rebar piece and secured with tie wire, perpendicularly, approximately two inches from the ground. Additional horizontal pieces may be wired to the vertical members as needed, perhaps spaced two or more inches apart.
As discussed above, the tie wire rolls, stretches, and vibrates loose. Additionally, because the vertical rebar members have such a small diameter (usually between ½ inch to one inch), the vertical rebar member loosens from the ground also. Particularly, the vertical rebar member may be kicked, vibrated loose, or the ground or soil may be undesirably soft for the vertical member to stay secured in the ground. In rocky terrain, the vertical rebar member may fall into a void, thus causing all the horizontal members to fall also, ultimately causing the entire rebar structure to fall from the required specification.
After the rebar has been laid and the cement is being poured, workers often have difficulty finishing the cement and ensuring a proper grade. This is particularly true for large pads of cement. In practice, the area that is to receive the cement is usually cordoned off with wood, such as 2×4's or 2×6's. Cement is poured in the cordoned area, and long leveling boards, pipe, or other devices are used to ensure that the cement pad is flat and level with the surrounding wood. The cement pad is flattened and leveled by moving the leveling board, pipe, or other device in a sawing motion, or spinning, or vibrating the board or pipe across the wood border.
Many areas, however, may not be cordoned off with wood, rather the area to receive the concrete is between existing walls. In such situations, screeds are placed atop the vertical rebar pieces and a pipe is laid over the screeds. The concrete is poured over the screeds and the pipe. The area is flattened and leveled by moving the leveling board or the leveling pipe, or other device, over the pipe that has been laid over the screeds. Excess concrete is removed. For this reason, it is imperative that the vertical rebar stays at a fixed position in the ground. If the vertical rebar becomes loose, or falls into a void in the ground, the concrete will not be level and may therefore gather puddles, crack, and appear unsightly.
What is needed is a device, system, and method that securely holds the vertical rebar members in a fixed position in a surface.